1、Lessons Learned Entry: 0125Lesson Info:a71 Lesson Number: 0125a71 Lesson Date: 1992-08-21a71 Submitting Organization: KSCa71 Submitted by: Lisa L. MusgraveSubject: Orbiter Compartment Overpressurization Description of Driving Event: The portable purge unit supplies conditioned air through ducts to t
2、he orbiter to purge and/or pressurize the payload bays forward and aft compartments. Airflow varies between 50 lbs/min minimum to 100 lbs/min maximum. Vent door observers are always on station when a vent door is repositioned for a test or TPS tile/thermal barrier work. Overpressurization may occur
3、if all the orbiter vent doors (normally in the purge position) for a compartment are closed at one time. Control logic program VAM09 also notifies the firing room engineers if both a right hand and left hand purge vent door set is closed.Lesson(s) Learned: Normal purge air applied to the orbiter com
4、partment while the vent doors are closed may cause major orbiter damage.Recommendation(s): Specify in work document that vent doors must remain in standard purge configuration and all on-board vent door circuit breakers remain “open“.Evidence of Recurrence Control Effectiveness: N/AProvided by IHSNo
5、t for ResaleNo reproduction or networking permitted without license from IHS-,-,-Documents Related to Lesson: N/AMission Directorate(s): a71 Space Operationsa71 Exploration SystemsAdditional Key Phrase(s): a71 Ground Operationsa71 Launch VehicleAdditional Info: Approval Info: a71 Approval Date: 1994-06-02a71 Approval Name: James G. Klinea71 Approval Organization: KSC/HEIa71 Approval Phone Number: 407-867-7614Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
